Conventionally, a pixel defect of a solid-state image pickup device of a television camera has been detected by comparing image signals of respective spectral lights obtained by dispersing incident light, the image signals being taken by image pickup devices at a same image pickup position or substantially same positions of the dispersed spectral lights. Then, based on the comparing result, a pixel defect in an image pickup device which has imaged one of the spectral lights is detected, and corrected (e.g., see Japanese Patent Laid-open Application No. 2002-44688).
Since random noise components are superimposed on each of image signals taken by the image pickup devices, a detection error is introduced in a pixel defect detection signal, so that it is difficult to detect a pixel defect having a level less than that of the random noise. For this reason, the conventional method has only limited applications, such as an extended exposure type camera and the like, of which the pixel defect detection signal level is relatively greater than the random noise.